Leading exhibition and event display provider Nimlok has an impressive record when it comes to avoiding the temptation to simply throw used materials away. In fact, many of the custom-made items produced by the Wellingborough-based firm are still in use 20 to 30 years after their construction.

The company was the first in its industry to achieve certification for the internationally recognised ISO 14001 environmental standard. And just one other company on our list gained a better positive green score (94%) for employees knowing what the ISO 14001 is. Staff also agree their organisation is well run (86%) and that colleagues think green (89%).

A "build and burn" mentality has dominated the display and exhibition industry. However, since it was founded in 1970, Nimlok has had a policy of reusing materials wherever possible.

The firm also shows its commitment to recycling by offering to dispose of unwanted equipment as part of its purchase agreement with clients.

Employees believe the firm does everything it can to minimise its environmental impact (89%) and believe it is getting better at protecting the environment (94%), both top 20 scores.

Nimlok operates a recycling programme for paper, cardboard and aluminium. Where possible, the firm has moved away from paper, culminating in a 50% reduction in printed matter in the past two years.

The organisation meets its environmental targets year on year, according to employees (82%), and they know where to put waste for recycling (96%, another top 20 score).

Environmental awareness is ingrained in the firm's culture. The company provides environmental training for new employees and continually refreshes it. The firm also has an environmental employee of the month award.

Staff say the training they receive at work makes them think differently about what they do at home (79%), people in their business do not associate green issues with beards and sandals (88%), and they are clear about Nimlok's green policy (90%).

The firm also avoids using solvent-based printing methods. Nimlock will even arrange the safe disposal or recycling of any lights or electronic equipment that it has supplied as long as it is returned by customers in a non-contaminated condition.

Staff say their departments are audited for their environmental performance (83%, a score bettered by just five other companies). Not only do bosses encourage recycling (89%), but they are also open to suggestions for green improvements (90%) and committed to the environment (91%).